The posthypnotic influences of suggestion belong to the most important phenomena of hypnotism. Everything which is produced in hypnosis itself can very frequently be called forth also in the waking condition by giving the suggestion to the hypnotized person during hypnosis that it will take place after he has awakened. Not every hypnotized person is posthypnotically suggestible. However, with a little practice and perseverance, one can achieve posthypnotic effects in nearly all sleepers, and even in many cases of simple hypotaxis without amnesia.

Examples

I say to a hypnotized: "When you awaken, you will get the idea of placing that chair on the table, and will then tap me on the left shoulder with your right hand." After having told him other things, I say: "Count up to six, and you will awaken." He counts, and when he reaches six he opens his eyes. For a moment he looks sleepily in front of him, then regards the chair and fixes it with his eyes. There is frequently a struggle between reason and the powerful impulse of the suggestion. According to whether the suggestion is unnatural or natural, on the one hand, and to the suggestibility of the subject on the other, the victory is gained either by the former (reason) or by the latter (the suggestion). But I have repeatedly observed, just as other experimenters have also done, that the attempt to resist the impulse of the suggestion may have bad effects when there is marked suggestibility. The hypnotized becomes anxious and excited, and is tortured by the thought that "he must do this thing." In two cases the hypnotized was ready even to undertake a walk of three miles. On one occasion it was to tap me on the shoulder, and on another it was to hand Miss Y. a towel. This impulse may last for hours or days. At other times it is weak, and may even be only a thought, like the remembrance of a dream, which does not impel one to action, and thus the suggestion is not carried out. The hypnotized person only looks at the object, or may not even do that. Still, one can produce the impulse, and eventually have it carried out, if one repeats the suggestion in such cases during hypnosis energetically. Our hypnotized has regarded the chair steadily; suddenly he gets up, takes the chair, and places it on the table. I say: "Why do you do that?" His answer may vary according to his temperament, education, and character, and the quality of the hypnosis. One person may say: "I believe that you have told me to do it during my sleep." The second may say: "I believe that I dreamed something about it." The third acknowledges in astonishment: "I was simply forced to do it; I don't know why." A fourth says: "I got the idea that I ought to do it." Another may give a reasoning motive that he found the chair in his way, and that it annoyed him. In the same way, if the latter has been told in the suggestion that he would fetch a towel and dry his face, he would say that he was sweating profusely. Lastly, the sixth has lost all remembrance of it as soon as he has carried it out. He believes that he had just awakened. It is especially in the last-named case that the action acquires (he appearance of somnambulism. His gaze is more or less fixed, and his movements have a certain automatic character, which, however, is lost after he has carried out the action. If one does not make the experiment ridiculous, and if it is carried out for the first time with the subject; if he does not know anything about hypnotism, and was rendered fully amnesic during the period of the hypnosis, he will not guess that the hypnotist was the sinner, the instigator of his actions. At least, this is so according to my belief and my experience. Some people, however, suspect the hypnotist, either because of the dreamlike remembrance of the suggestion during the hypnosis, or because the same experiment has been carried out with the same subject before; or because they have seen it carried out in others, or have heard or read about such an experiment; or because the whole thing was too idiotic, too nonsensical or unnatural, for them to have originated it spontaneously.

I have said to another hypnotized person: "When you awake you will see me entirely dressed in scarlet, and with two horns of a chamois buck on my head. Apart from this, my wife, who is sitting next to me, will have disappeared, and the door of the room, too, will be gone, and will be replaced completely by wallpaper and paneling, so that you will be compelled to leave the room by the other door." I then speak of other things, and tell the hypnotized person by suggestion to yawn three times and to awaken. He opens his eyes, rubs them several times, as if he is trying to remove a haziness, looks at me, begins to laugh, and rubs his eyes again. "Why are you laughing?" "You are quite red, and have two chamois horns on your bead," and so on. "Your wife has gone." "Where was she sitting?" "On that chair." "Do you see the chair?" "Yes." I ask him to feel the chair. He does this unwillingly, feels all around my wife, and believes that he is touching either the chair or an invisible resistance, according to the way in which he has complemented the suggestion by autosuggestion. He then wants to go, but cannot. He only sees wallpaper and panels, and states this while he is touching the door. If I should now open the door, the hallucination may either disappear or continue, in which latter case he sees the space filled with wallpaper and panels, but does not see the open door. Such posthypnotic hallucinations can last for a few seconds or hours, or in rare cases even for days, according to the suggestion and to the subject. As a rule, they only last a few minutes, 1 have attempted to have drawings made on white paper of that which I have suggested to the hypnotized. The drawings mostly turned out badly. The people stated that they could not see the outlines distinctly. However, some were not so bad. A very reliable and educated lady, who is related to me, drew the outlines of her suggested photograph quite well. However, she could draw very well, and the whole subject depends largely on this. People who cannot draw obviously hallucinate incorrectly, as they have never learned to conceive and also to perceive quite correctly. Bernheim tells of a lady who could not say whether a suggested rose was real or suggested. I have often made the following experiment: I have said to Miss Z., during hypnosis that she would find two violets on her lap, both of which should be natural and pretty, when she awakened; she would give me the prettier one of the two. At the same time, however, I laid one real violet on her lap. On awakening, she saw two violets; the one was paler and prettier, she told me, and gave me the corner of her white handkerchief, while she kept the real violet for herself. I asked her if she thought that both violets were real, or if one of my evanescent presents, of which she had previous experience, were among them. She said that the paler violet was not real, as it looked so flattened on her handkerchief. I repeated the experiment, with the suggestion of three real, equal-colored, not flattened violets, which were to be possessed of stalk and leaves, and which should be palpable and sweet-smelling. This time I only gave her one real violet. She was completely deceived, and could not tell me whether one of the three, or two, or even all three, were real or suggested. She thought that all three were real this time. At the same time, she held up one hand with nothing in it, and the other hand with the real violet in it. One can thus see that if one suggests the deception for all the senses it will be more complete. I have given another hypnotized a real knife, and told her that there were three. She was fully awake at the time, and could not distinguish the supposed three knives from one another, either when she cut with them, or when she felt them or knocked them against the window, etc She cut a piece of paper stretched out for her quite seriously, with nothing in her hand, and stated that she saw the cut, which did not exist, which she had made with the suggested knife. On asking her to pull the two parts of the paper {imagined only as two) asunder, she believed that the resistance which she felt was caused by my hypnotic influence. Later, when other people laughed at her, she got quite angry, and maintained that there were three knives, only I had secreted two of them later on. She had seen all three, had felt them, and heard them, and would not be convinced about the whole incident. On suggesting to the same person the disappearance of a real knife, she did not feel it when it lay in her hand, did not hear it drop, and did not feel anything when I pricked her with it, etc.

Feelings, thoughts, resolutions, etc., can be just as well suggested posthypnotically as hypnotically. The results obtained with the alcoholic woman mentioned in a preceding page and with the menstruation of women were posthypnotic On two occasions only I was able to produce or to control the menstruation at once during the hypnosis itself.